While everyone knows don t they? that regular aerobic exercise is good for your circulation and waistline, few are aware of another important benefit: reduced risk of breast cancer.
Despite practicing internal medicine for 20 years, I only learned of this recently, when my public health group, the American Council on Science and Health, reviewed a new study for our daily newsletter.
A group of scientists from the University of North Carolina-Chapel Hill compared thousands of women, half of whom had breast cancer and half cancer free. They analyzed the women s exercise histories, seeking a link between recreational physical activity, done at different time points in life, and the risk of developing breast cancer. (They also tabulated information about other possible risk factors for breast cancer, and adjusted the exercise-cancer results accordingly).
Here s what they found: Women who exercised either during their reproductive or postmenopausal years had a reduced risk of developing breast cancer. Women who exercised 10 to 19 hours per week experienced the greatest benefit with an approximate 30 percent reduced risk. While it may seem like a lot of time spent exercising, the authors included household and occupational activities in their tally, in addition to recreational exercise.
http://www.ncbi.nlm.nih.gov/pubmed/22733561
And here s even more good news: women who only began exercising during their post-menopausal golden years still benefitted from a significant reduction in breast cancer risk.
That study was published in Cancer: A Journal of the American Cancer Society. In that same issue, another expert in breast cancer and exercise noted the large number of prior studies showing similar reductions in breast cancer among women who exercise even moderately; specifically, any activity that was of at least moderate intensity, as long as it was maintained over periods of time. The intensity need not be greater than a brisk walk!
No one knows precisely why exercise has such an effect on breast cancer; and one downside should be noted weight gain eliminates that beneficial effect.
Bottom line: Ladies, if you keep active, no matter your age or available time, your heart health and your breast health will benefit.